上颌第三磨牙的外形特征及临床意义  

THE EXTERNAL CHARACTERISTICS AND CLNICAL SIGNIFICANCE OF THE MAXILLARY THIRD MOLAR

作　　者：罗传富[1] 王国华[1] 尹杨[2] 

机构地区：[1]泸州医学院解剖教研室 [2]西南师范大学医院口腔科

出　　处：《泸州医学院学报》1993年第3期178-181,共4页Journal of Luzhou Medical College

摘　　要：对213颗左侧上颌第三磨牙的外部形态进行了观察和比较,发现:①上颌第三磨牙有5种类型,即双尖牙型占9.4$,三尖型占52.6％,四尖型占33.8％,五尖型点3.3％,六尖型占0.9％;②上颌第三磨牙牙根可分为融合根型占48.8％,双根型占32.9％,三根型占18.3％,其中双尖牙型、三尖型以融合根为主而融合根的根尖均有一向远中弯曲的钩,四尖及其以上各型以双根和三根为主。为临床拔除此牙根供参考依据。The maxillary third molar i made up of the crown, root and neck, The occlusal surface of the crown have five types: bicusped, tricusped, quadricusped, pentacusped and hexacusped, in whieh 86.4% are the tricusped and quadricusped types. one root (fused root), two roots and three roots can be observed. The maxillary third molars of the bicusped and trieusped types mostly have one root (fused root), but their distal surfaces have a uniform incurvation. The maxillary third molar of the quadricusped. pentacusped and hexaeusped types have two or three roots. The clinieal significance for are above also has bee discussed.

关 键 词：上颌 第三磨牙 HE面 牙根 外形特征 

分 类 号：R782.1[医药卫生—口腔医学]